Introgen Therapeutics, Inc. announced that it has been awarded Patent No. 6,689,600 by the US Patent and Trademark Office. The patent, titled "Formulation of Adenovirus for Gene Therapy," covers Introgen's technology for producing long-term storage stable adenovirus. Such storage-stable formulations described in the patent may eventually replace formulations currently in use by the adenovirus industry by providing conveniences and efficiencies in storage, distribution, pharmacy handling and clinical administration.

Adenoviral particles intended for human therapeutic applications must maintain their structural integrity to remain biologically active. The structural integrity of a viral vector, if not handled properly, can be compromised during the formulation process. Indeed, extended periods of storage of adenoviral vectors in traditional formulations can exhibit diminished biological activity. For this reason, current adenoviral therapeutics are typically formulated in buffers containing glycerol, which permits their storage for extended periods. However, such formulations must be maintained and transported at extremely low temperatures.

Introgen's patent addresses the need for formulations that permit the long-term storage of adenoviral therapeutics under regular refrigerated conditions. Scientists from Introgen's adenoviral formulations group have discovered that the inclusion of one of a series of "bulking" agents together with one or more "protectants" permit adenoviral therapeutics to be maintained for over a year in regular refrigerated conditions (4 degrees) with very little loss of biological activity, and several years longer if stored under regular freezer conditions (-20 degrees).

"This patent represents a milestone in the development of long-term storage-stable viral formulations," said David Parker, Introgen's vice president of intellectual property. Dr Parker continued by noting "this patent represents very broad enabling technology, and covers the general concept of employing conventional pharmaceutical additives that were surprisingly found to promote the long-term storage stability of viral preparations."